Vacuum still



' J. H. HILLS June 13, 1933.

YACUUM STILL Filed Sept. 6, 1928 Patented June 13,1933" UNITED STAT es "P Te roFl-ica Joint mum! ms, or camp na'rms. moment, sss'rexon rofnousum mire. co.,

a OOBPORAIION or moment v VACUUI STILL Application filed September 8, 1928. Serial Io. 304,245.

This invention relates to. distilling apparatus operated under a partial vacuum to-reduce the temperature r uired for distilling the liquid being treate As a articular embodiment of this invention, a ydrocar bon still such as is used to purify dry cleaning agents has been selected for illustrative pur oses. v

eretofore, such vacuum distilling apparatus has comprised a closed still having means for heating the same and means for agitating theliquid therein, the still being connected to a coolin condenser '.for the gases driven ofi from t e liquid by the heatingthereof, together with a vacuum pump for removing non-condensed va ors and air from the condenser and still. 0 commence the operation of such a distillin apparatus, a vacuum must first produce and to deend u on a vacuum ump to exhaust the air rom t e still and condenser wouldinvolve considerable delay even though the pump were several times as large as required for maintaining the desired vacuum, when once established. v

It is accordingly an object of this invention to provide an inex ensive and reliable means for quickly estab ishing a desired degree of vacuum. In order toaccom lish this result, I provide a steam nozzle or intro ducing steam into the space above the liquid in the still and introduce su'flicient steam to drive or dis lace the air. out of the still and condenser. e condenser promptlyacts to condense this steam to water, thus producing an initial vacuum which can then be maintained by a relatively small vacuum pump which would otherwise be inadequate to produce the initial vacuum within 'a reasonable time. An advantage, of my invention lies in the coaction of the steam with the condenser after the steam has displaced the air initial- 1 in the system, thus 'economi'zing in size of "vacuum pump gr uired as well as efiecting a substantial saving of time required for starting. g

It is also an object of this invention to provide a method for producing a vacuum that can utilize the normal steam supply required for heatirigand agitating the liquid in the steam, thus reducing the cost of building and I installing a vacuum distllling apparatus.

Other and further important objects of this invention will be apparent from thedis closures in the specification and the accom panying drawing. 4

T is invention (in a preferredform) is illustrated in the drawing and hereinafter more fully described.

On the drawing: 4 1 The single figure is a vertical section through a vacuum distilling apparatus embodying the features of this invention.

As shown on the drawing:

The still proper comprises a cylindrical vessel 10 having a removable cover. 11 bolted to a flange 12 on the shell 10 and a removable double bottom 13 and 14 defining a steam 21, the flow of steam drawing li uid from the p still into the nozzle 21 throug a series'of holes 22 to increase the agitating efi'ect of the entering An outlet 23. for distilled vaporris provided in t e cover 11 and leads to a condenser 24 of any suitable type, which in turn is connected to a vacuum? 'um 25.

. A device for accomplish ng t e method of the present invention comprises a steam supply pipe 26 havin -a valve 27 and leading to a depending nozz e 28 ositioned above the level of the liquid 29 in t e still. An inverted conical baflle 30 is suspended in spaced relationship to the cover 11 by braces 31 and serves to cause a flow of gases and steam up along the walls of the still, any moisture condensing on the baflle draining back to the still through-a hole 32 in the tip of the cone.

The method of the present invention comprises initially establishing a vacuum by displacing the air and non-eondensible gases in the u per part of the still and condenser by intr ucing steam, which acts to displace the sir, drivin the air ahead of the steam and out throng the vacuum pump. The condenserin turn acts upon the steam to reduce it to water so that in conjunction with the vacuum pum. the condenser can quickly pro duce the desired degree of vacuum after introducing suficient steam to fill the guseous spaces in the still end condenser.

It will thus be seen that l have invented an improved method for quickly estuhlishing a desired degree of vacuum in a still which reduces the capacity of the vacuum pump required and also materially reduces the time required to place the still in operation.

ll um uwsre that many changes may he made, and numerous details of construction may be varied through a Wide range Without departing from the principles of this invention, and l therefore do not purpose limiting the patent granted hereon, otherwise than necessitated by the prior urt.

ll claim as my invention:

A vacuum still comprisin u closed vessel normally partially filled wit e liquid thereby defining a vapor space uloove suid liquid, a condenser, s vacuum pump for said condenser, a conduit connecting said condenser and said vessel above said liquid to curry ill vapor from the vuporspuce, menus to host said liquid for normal operation of said still, and means to initially remove air from the vapor space when the liquid is below normal operating temperature, suid meuns comprising at nozzle positioned in the vessel intermediste the liquid and the conduit connection to eject steam ungulnrly e ainst the surface of the liquid wherehy air and steam ure passed through said condenser to produce an initial vacuum in the still. v

In testimony whereof l have hereunto suhscrihed my name at Grand Rapids, Kent County, Michigan.

JUHN H. HEELS misses 

